What file format gives the best print quality?

For commercial printing, a press-ready PDF gives the most reliable results. PDF/X-1a and PDF/X-4 are built for print because they lock down the elements a printer needs to reproduce your file exactly.

• PDF/X-1a or PDF/X-4: preserves vector artwork, embeds fonts, and supports CMYK color.
• TIFF: a solid alternative for photo-heavy files that are mostly image.
• Avoid PNG and GIF: they are built for screens and do not support CMYK color.
• Avoid JPEG for final art: compression can soften edges and shift color.

When in doubt, export a flattened, high-resolution PDF/X with fonts outlined or embedded and bleed included.